This study was carried out to investigate the ecological characteristics of Protaetia orientalis submarmorea (Burmeister). The emergence period of adults is appeared from April to October, and most abundant in July∼August, once a year in the field. Hibernation took place mostly in larval stage, but some in adult stage, and were generally found in the decayed rice straws and in the soil covered with compost or similar materials with average depth of 17.6 cm The developmental characteristics in the insectary (28$^{circ}C$, 70% RH, 16L: 8D) was investigated: the average number of eggs laid per female is 82.8, egg period 8.4 days, 1st instars of larva 10.6, 2nd 18.7, 3rd 38.1, and pupal period 35.5 days. Longevity of the adult was 135.2 days In the female and 121. 7days in the male.